I believe a Makefile-To-[Whatever] is really hard to achive - I'd even say impossible. I've seen so many Makefiles in my life and trust me - some of them don't even share a single design element in common.
Anyway: I personally don't find it too hard to "port" a Makefile project to C::B (I have done it many times) as you can usually see the command line that is executed for each compilation step. I note down the settings (defines, includes, libs etc.), then import all files into a new projects and adjust the settings accordingly. Until now this worked very well also for large enterprise applications.
With regards, Morten.